I would like to remove the front mud flaps as I am painting the wagon tomorrow. The bolts just spin. I removed the mud guard so I could get a look at the back of the bolts with a dental mirror. There are two plastic tabs on both sides of the nut which will not allow my socket to fit over them. I also can't figure out if it is a 8 or 10 mm.

There isn't any room to get a wrench back there either. It seems as though I would have to take the whole fender off to gain access to the bolts to get them off. I don't really feel like doing that.

I just went through this. The tabs and bolts become so rusted from salt spray that there are very few options to remove them. I ended up bending the fender lip out slightly so that I could fit a pair of lock-jaws to the bolt, clamped down as hard as I could to keep it from spilling and then drilled out the bolt.